Which of the following is a requirement for underground conductors?

Underground conductors must have a warning ribbon placed 12 inches above them as a safety measure. This requirement serves multiple purposes. Primarily, the warning ribbon alerts anyone who may be excavating in the area that there are underground electrical conduits below, reducing the risk of accidental contact that could lead to serious injuries or damages. The visible marker provides a precautionary indicator, encouraging caution during digging or construction activities nearby.

While additional requirements may pertain to the burial depth, insulation materials, or encasement methods of underground conductors, the presence of a warning ribbon directly addresses safety in terms of awareness of existing underground installations. This measure is crucial to ensure both public safety and the integrity of the electrical system.